Public emergency information networks have been used for decades to field emergency calls and to direct those calls to an appropriate emergency service provider. In early systems, the calls were invariably conventional voice calls using the public switched telephone network (“PSTN”).
With the advent of multiple telecommunication formats, it has become possible, in principle, to call for help using formats other than voice calls over the PSTN. Such formats include, for example, text messages, e-mails, and calls made using voice over internet protocol (“VOIP”).
In recognition of the many new ways to call for help, NG9-1-1 (“Next Generation 9-1-1”) has been developed. Among its capabilities is that of receiving and sending communications in a variety of formats. This system is of considerable value to the hearing impaired, who have long had difficulties using the conventional 9-1-1 system in part because of its reliance on voice calls.
The 9-1-1 system is not a single national system, but an internetwork of local 9-1-1 call centers. Each such call center will decide if and when to upgrade to NG9-1-1. Each such call center will upgrade, if at all, following its own deployment schedule consistent with its own needs and capabilities. As a result, there will be a significant period of time, possibly on the order of years, during which a caller in need of help may not know the capabilities of the particular call-center his emergency call will ultimately be routed to.
In general, a caller who knows this will revert to the lowest common denominator. He will simply place a call using the PSTN. However, not all callers will have the presence of mind to do so, particularly in an emergency. It is possible for a caller whose own local service has implemented NG9-1-1 to be on the road and to naively assume that all other call-centers support similar service. In such cases, the caller may send a text and assume that the emergency call center will receive it. Such a mistake could be the last the caller ever makes.